The invention relates to a chain hoist having an electric drive motor which is connected to a gearbox by means of a slip clutch.
German patent DE 102 44 865 B4 already discloses a chain hoist having an electric drive motor which, by means of a gearbox connected downstream of the drive motor, drives a chain wheel for a chain for lifting and lowering a load. In order to avoid gearbox or drive motor overload e.g. when the chain is hooked onto the no-load side, a slip clutch is disposed between the drive motor and the gearbox. The slip clutch consists of a first annular clutch element and a second annular clutch element which are in engagement via a friction lining. The first clutch element is disposed concentrically on a driven-side end of a motor shaft of the drive motor and is connected in a rotationally fixed manner to the motor shaft. The second clutch element is disposed in a comparable manner on a first end of a gearbox input shaft of the gearbox. In order to be able to adjust the activation force of the slip clutch, the gearbox input shaft is disposed in an axially displaceable manner and the gearbox input shaft together with the second clutch element is pretensioned in the direction of the first clutch element by means of a spring element.
Furthermore, U.S. Pat. No. 3,396,557 A discloses a hammer drill which is driven by means of an electric motor. The electric motor is connected to receiver for a drilling tool by means of a gearbox. Disposed inside the gearbox is a slip clutch to be activated in the event of a pre-settable torque which acts upon the drilling tool. The slip clutch comprises a cylindrical housing which on its outer side comprises radially circumferential and outwardly directed fins. These fins should allow rapid dissipation of heat from the housing.